job platforms: Forward lookup

cylc/flow/exceptions.py

@@ -167,3 +167,8 @@ class CylcMissingContextPointError(CyclingError):
 
 class CylcMissingFinalCyclePointError(CyclingError):
     """An error denoting a missing (but required) final cycle point."""
+
+
+class PlatformLookupError(CylcConfigError):
+    """Unable to determine the correct job platform from the information
+    given"""

cylc/flow/platform_lookup.py

@@ -0,0 +1,98 @@
+# THIS FILE IS PART OF THE CYLC SUITE ENGINE.
+# Copyright (C) 2008-2019 NIWA & British Crown (Met Office) & Contributors.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# Tests for the platform lookup.
+
+import re
+from cylc.flow.exceptions import PlatformLookupError
+
+
+def forward_lookup(platforms, job_platform):
+    """
+    Find out which job platform to use given a list of possible platforms and
+    a task platform string.
+
+    Verifies selected platform is present in global.rc file and returns it,
+    raises error if platfrom is not in global.rc or returns 'localhost' if
+    no platform is initally selected.
+
+    Args:
+        job_platform (str):
+            platform item from config [runtime][TASK]platform
+        platforms (dictionary):
+            list of possible platforms defined by global.rc
+
+    Returns:
+        platform (str):
+            string representing a platform from the global config.
+
+    Example:
+    >>> platforms = {
+    ...     'suite server platform': None,
+    ...     'desktop[0-9][0-9]|laptop[0-9][0-9]': None,
+    ...     'sugar': {
+    ...         'login hosts': 'localhost',
+    ...         'batch system': 'slurm'
+    ...     },
+    ...     'hpc': {
+    ...         'login hosts': ['hpc1', 'hpc2'],
+    ...         'batch system': 'pbs'
+    ...     },
+    ...     'hpc1-bg': {
+    ...         'login hosts': 'hpc1',
+    ...         'batch system': 'background'
+    ...     },
+    ...     'hpc2-bg': {
+    ...         'login hosts': 'hpc2',
+    ...         'batch system': 'background'
+    ...     }
+    ... }
+    >>> job_platform = 'desktop22'
+    >>> forward_lookup(platforms, job_platform)
+    'desktop22'
+    """
+    if job_platform is None:
+        return 'localhost'
+    for platform in reversed(list(platforms)):
+        if re.fullmatch(platform, job_platform):
+            return job_platform
+
+    raise PlatformLookupError(
+        f"No matching platform \"{job_platform}\" found")
+
+
+def reverse_lookup(task_job, task_remote, platforms):
+    """
+    Find out which job platform to use given a list of possible platforms
+    and the task dictionary with cylc 7 definitions in it.
+
+    Args:
+        task_job (dict):
+            Suite config [runtime][TASK][job] section
+        task_remote (dict):
+            Suite config [runtime][TASK][remote] section
+        platforms (dict):
+            Dictionary containing platfrom definitions.
+
+    Returns:
+        platfrom (str):
+            string representing a platform from the global config.
+
+    Examples:
+        Tim - write some doctests here...
+
+    """
+    raise NotImplementedError

cylc/flow/tests/test_platform_lookup.py

@@ -0,0 +1,87 @@
+# THIS FILE IS PART OF THE CYLC SUITE ENGINE.
+# Copyright (C) 2008-2019 NIWA & British Crown (Met Office) & Contributors.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# Tests for the platform lookup.
+
+import pytest
+from cylc.flow.platform_lookup import forward_lookup, reverse_lookup
+from cylc.flow.exceptions import PlatformLookupError
+
+PLATFORMS_STANDARD = {
+    'suite server platform': None,
+    'desktop[0-9][0-9]|laptop[0-9][0-9]': None,
+    'sugar': {
+        'login hosts': 'localhost',
+        'batch system': 'slurm'
+    },
+    'hpc': {
+        'login hosts': ['hpc1', 'hpc2'],
+        'batch system': 'pbs'
+    },
+    'hpc1-bg': {
+        'login hosts': 'hpc1',
+        'batch system': 'background'
+    },
+    'hpc2-bg': {
+        'login hosts': 'hpc2',
+        'batch system': 'background'
+    }
+}
+
+PLATFORMS_NO_UNIQUE = {
+    'sugar': {
+        'login hosts': 'localhost',
+        'batch system': 'slurm'
+    },
+    'pepper': {
+        'login hosts': ['hpc1', 'hpc2'],
+        'batch system': 'slurm'
+    },
+
+}
+
+PLATFORMS_WITH_RE = {
+    'hpc.*': {'login hosts': 'hpc1', 'batch system': 'background'},
+    'h.*': {'login hosts': 'hpc3'},
+    r'vld\d{2,3}': None,
+    'nu.*': {'batch system': 'slurm'}
+}
+
+
+@pytest.mark.parametrize(
+    "PLATFORMS, platform, expected",
+    [(PLATFORMS_WITH_RE, 'nutmeg', 'nutmeg'),
+     (PLATFORMS_WITH_RE, 'vld798', 'vld798'),
+     (PLATFORMS_WITH_RE, 'vld56', 'vld56'),
+     (PLATFORMS_NO_UNIQUE, 'sugar', 'sugar'),
+     (PLATFORMS_STANDARD, None, 'localhost'),
+     (PLATFORMS_STANDARD, 'laptop22', 'laptop22'),
+     (PLATFORMS_STANDARD, 'hpc1-bg', 'hpc1-bg'),
+     (PLATFORMS_WITH_RE, 'hpc2', 'hpc2')
+     ]
+)
+def test_basic(PLATFORMS, platform, expected):
+    assert forward_lookup(PLATFORMS, platform) == expected
+
+
+def test_platform_not_there():
+    with pytest.raises(PlatformLookupError):
+        forward_lookup(PLATFORMS_STANDARD, 'moooo')
+
+
+def test_similar_but_not_exact_match():
+    with pytest.raises(PlatformLookupError):
+        forward_lookup(PLATFORMS_WITH_RE, 'vld1')